Accurate determination of fiber water-retaining capability at process conditions by headspace gas chromatography

• Determination of fiber water-retaining capability by headspace gas chromatography.
• The present method has a good precision and accuracy in the fiber water-retaining capability measurement.
• The method is also suitable to measure the fiber water retaining capability at elevated temperatures.

This work reports on a method for the accurate determination of fiber water-retaining capability at process conditions by headspace gas chromatography (HS-GC) method. The method was based the HS-GC measurement of water vapor on a set closed vials containing in a given amount pulp with different amounts of water addition, from under-saturation to over-saturation. By plotting the equilibrated water vapor signal vs. the amount of water added in pulp, two different trend lines can be observed, in which the transition of the lines corresponds to fiber water-retaining capability. The results showed that the HS-GC method has good measurement precision (much better than the reference method) and good accuracy. The present method can be also used for determining pulp fiber water-retaining capability at the process temperatures in both laboratory research and mill applications.